Note that the "four ports" on the router are actually a four-port switch 
built into the box.

  There are two possible approaches, and I can't unreservedly recommend 
either of them:

1.  Use a crossover to connect one of the eight LAN ports on the new device 
to one of the four on the old.  As you've noted, you need to disable the 
DHCP server on one device.
  The primary argument against this approach is the low return.  Since the 
crossover uses up a port at each end, your four-port device only nets you 
TWO additional ports.

2.  Connect the WAN port of the old router into one of the ports on the new 
box.  Configure its DHCP service and LAN-facing address to use a different 
subnet from the new device.
  Configure its WAN port to a static address in the space used by the new 
device.  You'll have to figure out how to make sure DHCP on the new device 
doesn't try to give this address to another client.
  Now you need to create a static *route* on the new device, telling it that 
the new subnet (first paragraph) is reached via the static address (second 
paragraph).
  This nets you three additional ports, but is obviously more work and 
harder to troubleshoot.

David Gillett



On 17 Sep 2006 at 20:38, Will Stephenson wrote:

Date sent:      	Sun, 17 Sep 2006 20:38:25 -0400
Send reply to:  	Personal Computer Hardware discussion List
             	<[log in to unmask]>
From:           	Will Stephenson <[log in to unmask]>
Subject:        	[PCBUILD] How do you turn a router into a switch?
To:             	[log in to unmask]

> I have a client whose network is beginning to grow beyond the 4 port router
> that had previously served them well. I'd like to attach the old 4 port
> router to the new 8 port router and have it act like a switch/hub. Is this
> possible? If so, what changes do I need to make to the old router to make
> that happen? (I did disable the old router's DHCP)
> 
> Thanks for your time and thought on this!
> 
> Will Stephenson
> Acadia Technologies Inc.
> mailto:[log in to unmask]
> 
> "It's the point of symbolic words to ease the burden of thought." 
> 
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